Circuit-Level Gateways
Circuit-level gateways are a type of firewall that work at the session layer of the OSI model, observing TCP (Transmission Control Protocol) connections and sessions. Their primary function is to ensure the established connections are safe.
Circuit-Level Gateways
Circuit-level gateways are a type of firewall that work at the session layer of the OSI model, observing TCP (Transmission Control Protocol) connections and sessions. Their primary function is to ensure the established connections are safe.
In most cases, circuit-level firewalls are built into some type of software or an already existing firewall.
Like pocket-filtering firewalls, they don’t inspect the actual data but rather the information about the transaction. Additionally, circuit-level gateways are practical, simple to set up, and don’t require a separate proxy server.
| CIRCUIT-LEVEL GATEWAYS | |||
| Advantages | Disadvantages | Protection Level | Who is it for: |
| – Resource and cost-efficient.– Provide data hiding and protect against address exposure.
– Check TCP handshakes. |
– No content filtering.– No application layer security.
– Require software modifications. |
– Moderate protection level (higher than packet filtering, but not completely efficient since there is no content filtering). | – They should not be used as a stand-alone solution.– They are often used with application-layer gateways. |
